1. Field of the Invention
The present invention relates to an antenna module, more particularly to an antenna having a relatively small size and high isolation.
2. Description of the Related Art
Multiple-antenna system (e.g., multiple-input and multiple-output systems, MIMO systems) is generally used to improve data rate and channel capacity. However, since mobile electronic devices are made increasingly smaller, distances between multiple antennas in the same mobile electronic device are getting shorter. When two antennas are close to each other and operate at the same resonant frequency band, coupling effect between the antennas will result in low isolation therebetween, which degrades performances of the antennas.
A conventional antenna module as disclosed in U.S. Pat. No. 8,085,202 for improving isolation between two antennas is to include, on a ground plane between the antennas, an isolation element in a form of a slot for providing isolation between the two antennas. Nevertheless, the isolation element having the slot configuration may increase the size of the conventional antenna module.
Another conventional antenna module as disclosed in U.S. Pat. No. D606,058 for improving isolation between two antennas is to include a thin metal strip that is connected electrically between the two antennas. However, to precisely adjust the thin metal strip, various considerations, parameters and factors need to be taken, thereby complicating the adjustment.